It is known, in the dyeing of textile materials, that the materials fibres must be subjected to the action of suitable dyes diluted in a dyeing bath at a temperature and for a time to be preset according to the nature of the same fibers and the type of dyes used.
One of the problems mostly felt in this industrial sector is the repeatability of the dyeing processes in relation to laboratory tests which are carried out for the preparation and verification of the formulations or "recipes". The dyeing performed during the industrial production stage, without a proper preventive laboratory check, may actually imply the need of correcting the formulation of the bath intended to feed the dyeing machines, which brings about extra costs, production delays, possible unevenness of the bath and consequent lower quality of the finished product.